couldn't agree more bud, but for me it has to be brain, as said in the post :- what does the collie bring ? if i wanted total commitment then a bull x would be the answer, but in my eyes they're a sledge hammer to crack a nut, pending what you want i find a good collie x whippet, collie x greyhound or beddie x whippet, beddie x greyhound hard to beat.